JP7748702B2 - plant cultivation equipment - Google Patents

Description

The present invention relates to a plant cultivation device used in a plant factory, and in particular to a plant cultivation device equipped with lighting equipment using LED light sources.

Plant cultivation devices using lighting equipment are used in facilities such as plant factories for cultivation. Plant cultivation devices are devices that grow plants using only artificial light, such as fluorescent tubes, or devices that control plant growth by supplementing lack of sunlight during the day with artificial light or by intentionally extending the hours of sunlight. Most lighting devices attached to conventional plant cultivation devices use fluorescent tubes, which are covered with shades and attached to the shelves or pillars of the plant cultivation device (see, for example, Patent Document 1). In recent years, there has been a shift from fluorescent tubes to LED light sources as the light source for lighting devices.

Since fluorescent tubes emit light in all directions, conventional plant cultivation devices place a shade above the fluorescent tubes and reflect the emitted light downward, thereby directing it toward the plants being cultivated. However, when using LED light sources for lighting, the light they emit is directional, so as in the plant cultivation device 101a shown in Figure 7(a), the LED light source 113a is positioned so that its radiation direction is directed toward the plants 133a in the cultivation tank 130.

However, the LED light source 113a is designed to only illuminate a certain range at a predetermined illumination angle (also called the directivity angle). As a result, when the illumination angle Ra of the LED light source 113a is approximately 60 degrees, uneven illuminance occurs near the panel surface of the cultivation tank 130, as shown in Figure 7(a). In other words, there are areas where the illumination ranges from adjacent LED light sources 113a overlap and areas where they do not, resulting in areas with high and low illuminance. As a result, there is an issue with short seedlings (plants 133a), where uneven light strikes them and causes differences in their growth.

To solve this problem, using an LED light source 113b with an illumination angle Rb of approximately 120 degrees, as in the plant cultivation device 101b shown in Figure 7(b), reduces uneven illuminance near the panel of the cultivation tank 130. However, uneven illuminance occurs near the LED light source 113b, and for tall plants 133b at harvest time, uneven light is received in the upper parts, resulting in differences in growth.

Two countermeasures can be considered to solve this problem. The first countermeasure is to increase the number of LED light sources 113b to eliminate uneven illuminance. The second countermeasure is to install the LED light sources 113 even higher, adjusting them so that uneven illuminance does not occur even at the top of the plants 133b during the harvest season.

In the first proposed solution, increasing the number of LED light sources 113b increases power consumption and heat generation. This, in turn, increases the air conditioning load required to remove the generated heat. In plant factories where plants are grown, the power consumption increases for both lighting and air conditioning equipment, so the first proposed solution poses the problem of increased plant cultivation costs.

The second solution has the advantage of easily leveling out uneven illuminance by increasing the installation height while keeping the number of LED light sources 113b constant. However, increasing the installation height of the LED light sources 113b reduces illuminance, which can slow plant growth and reduce quality.

JP 2012-182998 A

The present invention was made to solve the above-mentioned problems, and aims to provide a plant cultivation device equipped with lighting equipment that reduces the occurrence of uneven illuminance.

The above problem is solved by the plant cultivation device of the present invention, which is a plant cultivation device equipped with lighting equipment, wherein the lighting equipment comprises an LED light source, an LED board on which the LED light source is mounted, and a shade covering the LED light source and the LED board, wherein the shade has a curved reflective surface that includes a quadratic curve with the position of the LED light source as its focus in a vertical cross section passing through the LED light source, and the LED light source is arranged with its irradiation direction facing the reflective surface of the shade , and the plant being cultivated is irradiated with parallel light reflected by the reflective surface .

In the plant cultivation device of the present invention configured as described above, light from the LED light source is emitted toward the curved reflective surface of the canopy, which encompasses a quadratic curve. The LED light source is not pointed directly at the plants. As a result, light is emitted as parallel rays from the reflective surface of the canopy toward the plants. This suppresses uneven illuminance in the space where plants are cultivated (hereinafter sometimes referred to as the plant growth space), eliminating uneven growth from the seedling stage to the harvesting stage and enabling efficient lighting.

In addition, a preferred configuration for the above-mentioned cultivation device is that the LED substrate is formed in an elongated shape, multiple LED light sources are arranged in a linear line along the LED substrate, and the shade extends along the direction in which the multiple LED light sources are arranged.
By arranging the LED light sources in a straight line, it is possible to irradiate the light onto the elongated cultivation tank, thereby enabling efficient illumination.

Furthermore, a preferred configuration for the above-mentioned plant cultivation device is that the multiple LED light sources are arranged in two rows on the LED board, the reflective surface of the shade has a first region and a second region, the first region and the second region are arranged in positions that are line-symmetrical with respect to the center line of the reflective surface, the multiple LED light sources arranged in the first row are arranged so that their irradiation direction is toward the first region, and the multiple LED light sources arranged in the second row are arranged so that their irradiation direction is toward the second region.

Since LED light sources emit light at a predetermined angle, it is best to use multiple LED light sources to illuminate the entire reflective surface of the shade. For example, by arranging LED light sources with an illumination angle of approximately 90 degrees on the LED board and arranging them so that each is facing a different area of the reflective surface, it is possible to emit a wider, parallel beam of light toward the plants than when the LED light sources are arranged in a single row.

The above problem is solved by a plant cultivation device according to the present invention, which is a plant cultivation device equipped with a lighting device, the lighting device including an LED light source, an LED board on which the LED light source is mounted, and a shade covering the LED light source and the LED board, the shade having a curved reflective surface that includes a quadratic curve with a focus at the position of the LED light source in a vertical cross section passing through the LED light source, the LED light source is arranged with its irradiation direction facing the reflective surface of the shade, the LED board is formed elongated, a plurality of the LED light sources are arranged linearly along the LED board, and the plurality of LED light sources are arranged in three rows on the LED substrate, the reflective surface of the shade has a first region, a second region, and a third region, the first region and the second region are arranged in positions that are linearly symmetrical with respect to the center line of the reflective surface, the third region is located between the first region and the second region, the plurality of LED light sources arranged in the first row are arranged so that their irradiation direction is toward the first region, the plurality of LED light sources in the second row are arranged so that their irradiation direction is toward the second region, and the plurality of LED light sources in the third row are arranged so that their irradiation direction is toward the third region.

Furthermore, a preferred configuration for the above-mentioned plant cultivation device is that the plurality of LED light sources are arranged in a row on the LED substrate, and the LED substrate is arranged so that the irradiation direction of the LED light sources is inclined at a predetermined angle from the vertical direction in the longitudinal cross section.
When multiple LED light sources are arranged in a row on an LED board, if the LED light sources are arranged so that their irradiation direction is facing upward, the brightest part of the emitted light will be reflected straight off the ceiling surface of the shade and return to the LED board, creating a shadow.By arranging the LED board so that the irradiation direction is tilted at a certain angle from the vertical, the reflected light of the brightest part of the light will avoid the LED board and reach the plants.

Furthermore, regarding a preferred configuration of the above-mentioned plant cultivation device, the LED board on which the LED light source is mounted may be attached so as to be rotatable about an axis that is perpendicular to the longitudinal section and passes through the LED board.
Furthermore, a preferred configuration of the above-described plant cultivation device is to include a housing that surrounds the LED board and rotates together with the LED board around the axis.
Light reflected by the shade may be blocked by the LED board, creating a shadow. Although light reaches the shaded areas due to scattered light reflected from the floor, etc., uneven illuminance with different light intensities may remain in some areas. By rotating the LED board and the housing surrounding it and adjusting the light reflected from the shade's reflective surface, it is possible to alleviate uneven illuminance that occurs below the LED board, for example, or move the shaded area. In other words, the position of the light can be adjusted to provide appropriate illuminance according to the position and height of the plant, which varies depending on the growth stage.

Furthermore, a preferred configuration for the above-mentioned plant cultivation device is one in which the device is equipped with an air conditioning device, the air conditioning device having an air conditioning duct arranged below the LED board, and the air conditioning duct having an outlet through which air is blown toward the reflective surface formed on the reflective surface side of the shade.
By providing an outlet formed on the reflective surface that blows air toward the reflective surface, the cool air blown from, for example, an air conditioner, is agitated using the reflector. Since the cool air does not directly hit the plants, it is less likely to impede plant growth.

The plant cultivation device of the present invention can provide a plant cultivation device equipped with lighting equipment that reduces the occurrence of uneven illuminance.

FIG. 1 is a perspective view of a plant cultivation device according to an embodiment of the present invention. 2 is a cross-sectional view of the plant cultivation device taken along line II-II in FIG. 1. 3 is a cross-sectional view showing the lighting device, and is a partially enlarged view showing a portion A in FIG. 2 . FIG. 10 is a cross-sectional view showing another example of a lighting device. FIG. 10 is a cross-sectional view showing another example of the plant cultivation device. FIG. 10 is a cross-sectional view showing another example of the plant cultivation device. 1A and 1B are explanatory diagrams of a plant cultivation device equipped with a conventional lighting device using an LED light source, where (a) shows the case where the illumination angle of the LED light source is approximately 60 degrees, and (b) shows the case where the illumination angle is approximately 120 degrees.

The configuration of a plant cultivation device 1 according to one embodiment of the present invention (hereinafter referred to as this embodiment) will be described below using Figures 1 to 6. In the following embodiments, identical or similar components are designated by common reference symbols, and the scale of these drawings has been appropriately adjusted to facilitate understanding.

In addition, in this embodiment, as shown in FIG. 1, the direction in which the lighting device 10 and the cultivation tank 30 extend (arrow X direction) in the plant cultivation device 1 is the longitudinal direction of the plant cultivation device 1, and the direction of arrow Y extending laterally relative to the arrow X direction is the width direction. Furthermore, the direction perpendicular to the arrow X direction and the arrow Y direction is the height direction, and the direction of arrow Z is the upward direction (upper side), and the opposite direction is the downward direction (lower side).

<<Plant cultivation equipment>>
The plant cultivation device 1 of this embodiment is a device for hydroponically cultivating plants 33 in a plant factory, and is composed of a cultivation tank 30, a lighting device 10 installed in the cultivation tank 30, and an air conditioning device 20. Cultivation panels 32 float in the cultivation tank 30, and the panels are replaced as the plants 33 grow. The lighting device 10 is installed to illuminate the cultivation panels 32 and plants 33 floating in the cultivation tank 30.

The cultivation tank 30 is a long and narrow tank extending vertically (in the direction of arrow X in Figure 1), and is filled with a hydroponic nutrient solution 31. The cultivation panel 32 is made up of multiple replaceable panels and is capable of floating and moving.
Each cultivation panel 32 is a member on which a plurality of seedlings are planted at regular intervals (plant spacing pitch) and which supports the grown plants 33. In a plant factory, cultivation panels 32 formed with various plant spacing pitches are prepared according to the type or growth of the plants 33. The cultivation panels 32 are made using, for example, a foam material so that they float in the hydroponic nutrient solution 31, but may also be made from hollow resin, wood, etc.
The surface of the cultivation panel 32 has a high light reflectivity and also functions as a reflector that reflects light from the lighting device 10, directing light onto the plants from below.

<<Lighting equipment>>
Next, the lighting device 10 will be described. In plant factories, plants 33 are cultivated using lighting devices 10 that provide artificial light to reduce variations in plant growth due to inclement weather. In recent years, LED light sources 13 have been used instead of fluorescent tubes as artificial light. The lighting device 10 is composed of multiple lighting units 11. In the lighting device 10 of this embodiment, four lighting units 11 are arranged parallel to one another. The number of lighting units 11 is merely an example, and may be one or five or more lighting units to match the width of the cultivation tank 30. The four lighting units 11 can be attached and detached integrally using a support member 36. Side walls 34 are provided on the sides of the lighting device 10 to prevent light from leaking outside. As shown in FIGS. 1 and 2 , a gap 34a of several millimeters to several centimeters is formed in the side wall 34 at the boundary with the cultivation tank 30. This gap 34a allows the cold air in the plant cultivation space to escape, thereby suppressing temperature variations within the plant cultivation space.

Each lighting unit 11 has multiple LED light sources 13 arranged in a straight line and an elongated LED board 12 on which the multiple LED light sources 13 are mounted. Each lighting unit 11 also has a shade 14 that covers the multiple LED light sources 13 and LED board 12 and extends in the direction in which the multiple LED light sources 13 are arranged (vertical direction, arrow X direction).

The shade 14 has a curved reflective surface 15 that includes a quadratic curve in a vertical cross section including the LED light source 13, more specifically, in a cross section perpendicular to the direction in which the multiple LED light sources 13 are linearly arranged (vertical direction, arrow X direction). The LED light source 13 is positioned so that it is located at the focus of the quadratic curve of the reflective surface 15 of the shade 14. Therefore, as shown by the two-dot chain arrow in Figure 2, light emitted from the LED light source 13 is reflected by the reflective surface 15 and reflected toward the plant 33 as parallel rays. Because the light is irradiated onto the plant 33 as parallel rays, the area where it overlaps with the light emitted from the adjacent lighting unit 11 is reduced. This reduces uneven illumination, even from the seedling stage when the plant is still young to the height of the plant 33 at harvest time, and also reduces uneven growth of the plant 33. The shade 14 is made of metal or a resin with high light reflectivity.

A highly reflective material may be attached to the inner surface of the shade 14 to form the reflective surface 15 of the shade 14, thereby reducing light loss. Alternatively, a highly reflective material may be attached to the surface of the LED board 12 on which the LED light source 13 is mounted, thereby reducing light loss by re-reflecting the light reflected by the reflective surface 15. Examples of highly reflective materials include aluminum, silver, gold, copper, and cobalt. The highly reflective material may also be a highly reflective resin laminate plate in which highly reflective resin is laminated. Examples of highly reflective resins include resins containing white pigments such as titanium oxide. Highly reflective material may also be attached to the inner surface of the side walls 34, in addition to the shade 14.

The LED light sources 13 arranged linearly in each lighting unit 11 of the lighting equipment 10 will be described in more detail using Figure 3. LED light sources 13 typically emit light at a narrower angle than fluorescent lamps or light bulbs, and this angle is usually designed to be between 30 and 90 degrees, with the front (center) of the LED light source 13 being brighter and becoming darker as it extends outward. The smaller the angle of illumination, the greater the difference in illuminance between the front and the outside. In the following, the direction passing through the center of the illumination angle R of the LED light source 13 will be referred to as the illumination direction.

When using the reflecting surface 15 of the shade 14 to emit parallel light, it is desirable to use LED light sources 13 with a wide illumination angle; however, LED light sources 13 with a wide illumination angle are not common and must be custom-made, which increases costs. Therefore, in this embodiment, the LED light sources 13 are arranged in multiple rows on the LED board 12, and the reflecting surface 15 of the shade 14 is divided by the surface from which the LED light sources 13 in each row emit light, thereby providing parallel light with a wider width than when arranged in a single row.

Specifically, as shown in Figure 3, two rows of LED light sources 13 are arranged on the LED substrate 12. The LED light sources 13 have an illumination angle R1 of approximately 90 degrees. The reflecting surface 15 is divided by a center line C into a first region 15a and a second region 15b. The first region 15a and the second region 15b of the reflecting surface 15 are arranged in positions that are symmetrical with respect to the center line C. Of the two rows of LED light sources 13, the LED light sources 13a arranged in the first row are arranged so that their illumination direction is toward the first region 15a of the reflecting surface 15. On the other hand, the LED light sources 13b arranged in the second row are arranged so that their illumination direction is toward the second region 15b of the reflecting surface 15. In other words, the LED light sources 13a and 13b are arranged at an angle with respect to the center line C so that their illumination ranges do not overlap. By arranging multiple LED light sources 13 in this way, the reflective surface 15 of the shade 14 can be used to emit light over a wide area, allowing wide, parallel beams of light to be emitted toward the plants 33.

Each lighting unit 11 of the lighting device 10 may have three rows of multiple LED light sources 13A arranged on the LED substrate 12, as in lighting unit 11A shown in Figure 4. In this case, LED light sources 13A with an illumination angle R2 of approximately 60 degrees are used. The reflecting surface 15 is divided into three regions (first region 15Aa, second region 15Ab, and third region 15Ac), and the first region 15Aa and second region 15Ab are positioned symmetrically with respect to the center line C of the reflecting surface 15. The third region 15Ac is positioned between the first region 15Aa and second region 15Ab, as shown in Figure 4.

Of the three rows of LED light sources 13A, the LED light sources 13Aa in the first row are arranged so that their illumination direction is toward the first region 15Aa of the reflective surface 15. Meanwhile, the LED light sources 13Ab in the second row are arranged so that their illumination direction is toward the second region 15b of the reflective surface 15. The LED light sources 13Ac in the third row, located between the first and second rows of LED light sources 13Aa and 13Ab, are arranged so that their illumination direction is toward the third region 15Ac, which is above the LED light sources 13c. The LED light sources 13Aa-13Ac are arranged so that their illumination ranges do not overlap. By arranging multiple LED light sources 13 in this way, even when using an LED light source 13A with an illumination angle R2 of approximately 60 degrees, light can be irradiated across the entire reflective surface 15 of the shade 14, allowing parallel light to be irradiated onto plants across the width of the shade 14. Furthermore, increasing the number of rows of LED light sources 13 arranged on the LED board 12 makes it possible to irradiate plants with brighter light.

In this embodiment, the reflective surface 15 is used to provide indirect illumination, and the LED light source 13 is not aimed directly at the plants. As shown in Figures 7(a) and 7(b), if the LED light source 113 were aimed directly, uneven illuminance would occur depending on the height from the cultivation panel 132, which could result in differences in growth depending on where the plant is placed. In this embodiment, the lighting device 10 irradiates the plants with parallel light using the reflective surface 15 of the shade 14, thereby preventing uneven illuminance depending on the height from the cultivation panel 32.

Of the parallel light from the reflecting surface 15, light directed directly above the LED board 12 and the air conditioning duct 21 of the air conditioning equipment 20 (described later) is reflected straight back to the LED board 12. This may result in a shadow below the air conditioning duct 21. Light reflected by the cultivation panel 32 other than directly below the equipment such as the LED board 12 returns to the reflecting surface 15 of the shade 14 and is reflected again, eventually becoming scattered light. The scattered light also reaches the shadowed area below the air conditioning duct 21, but may remain as uneven illuminance where the light intensity varies locally.
To eliminate this unevenness in illuminance, it is desirable to be able to adjust the irradiation direction of the LED light source 13 in accordance with the position and height of the plant, which changes depending on the type and growth stage of the plant being cultivated.

In the lighting device 10A of the plant cultivation device 1A shown in Figure 5, the LED substrate 12A is rotatable about an axis 16 extending in the longitudinal direction of the LED substrate 12A, in other words, an axis 16 that is perpendicular to the longitudinal section and passes through the LED substrate 12A. The LED substrate 12A can be rotated clockwise or counterclockwise.

The irradiation direction of the LED light source 13 can be changed by rotating the LED substrate 12A around the axis 16 by any rotation angle θ. By changing the irradiation direction of the LED light source 13 according to the position and height of the plant, for example, the light from the LED light source 13 can be reflected from the side wall 34, etc., making it possible to reduce uneven illumination on the cultivation surface and move shadow areas.

Note that when there are multiple lighting units 11A, such as the lighting device 10A of the plant cultivation device 1A, the rotation angle θ of each LED board 12A does not need to be the same. For example, as shown in Figure 5, the rotation angle θ may be changed for each lighting unit 11A to achieve appropriate illuminance. In Figure 5, the LED board 12A of the lighting unit 11A located on the left side is rotated counterclockwise, and the LED board 12A of the lighting unit 11A located on the right side is rotated clockwise.

In this way, by rotating the LED substrate 12 and adjusting the light reflected from the reflecting surface 15 of the shade 14, even if the position or height of the plant changes depending on the type or growth of the plant, it is possible to appropriately apply light with reduced unevenness in illuminance to the plant.
In the lighting device 10A of the plant cultivation device 1A shown in Fig. 5, only the LED board 12A in each lighting unit 11A is arranged to rotate, but this is just an example, and the LED board 12A may rotate together with the air conditioning duct 21. The air conditioning duct 21 also serves as a housing surrounding the LED board 12A. The air conditioning duct 21 has an air passage 22 provided below the LED board 12, and is configured to blow air from an air outlet 23 provided on the side of the LED board 12A toward the reflective surface 15 of the shade 14 (see also Figs. 3 and 4).
By rotating the air conditioning duct 21 together with the LED board 12A, the blowing direction of the air ejected from the air outlet 23 can be changed.

In the embodiment shown in Figures 3 and 4, LED light sources 13 arranged in multiple rows were used, but increasing the number of LED light sources 13 increases power consumption, installation costs, and heat generation. Therefore, the lighting unit 11 may be constructed by arranging LED light sources 13C with a large illumination angle R vertically in a single row. However, if the LED light sources 13C are arranged in a single row with the illumination direction facing directly upward, the light in the illumination direction will be reflected straight off the ceiling surface of the reflective surface 15 of the shade 14. This reflected light returns to the LED board 12 and is blocked by the LED board 12 and the air conditioning duct 21 of the air conditioning equipment 20, which will be described later, creating a shadow. Although scattered light hits the shaded area, uneven illuminance occurs. Therefore, it is desirable for the light emitted in the illumination direction to avoid the LED board 12.

Another example of the plant cultivation device 1 will be described using Figure 6. The plant cultivation device 1B shown in Figure 6 uses an LED board 12B on which LED light sources 13B are arranged in a row. The LED light source 13B has an illumination angle R3 of approximately 140 degrees.

In plant cultivation device 1B, LED substrate 12B is installed so that the irradiation direction (indicated by arrow E) of LED light source 13B is tilted at a specified inclination angle β (predetermined angle) from the vertical direction (center line C) in a longitudinal cross section. This causes the brightest part of the light emitted from LED light source 13B to be reflected downward by reflective surface 15, as indicated by arrow F, avoiding LED substrate 12B. When the irradiation angle R3 of LED light source 13B is approximately 140 degrees, it is recommended that inclination angle β be around 20 degrees. In order to achieve uniform illumination on the cultivation surface, in accordance with the plant being cultivated and its growth stage, inclination angle β may be adjusted between 10 and 30 degrees.

The shape of the shade 14B in this case will be explained. Because the illumination angle R3 of the LED light source 13B is approximately 140 degrees, there will be a portion (portion G in Figure 6) where light from one LED light source 13B is not irradiated. If this non-irradiated portion G were formed as a parabolic surface like the shade 14 shown in Figures 3 and 4, little light would be reflected, which could result in uneven illuminance on the cultivation surface below. For this reason, a wall extending in the height direction (Z direction) is provided for portion G. A highly reflective material may be attached to the inside of the wall extending in the height direction to reflect the light from the LED light source 13B. The adjacent lighting unit 11B is then used to illuminate downward. In this way, the light from the bright portion irradiated by the LED light source 13B is no longer blocked by the LED board 12B and the air conditioning duct 21, allowing for efficient light irradiation and eliminating uneven illuminance.

<<Air conditioning equipment>>
Next, the air conditioning equipment 20 provided in the plant cultivation device 1 of this embodiment will be described with reference to Figures 2 to 4. In a plant factory, the internal temperature and humidity are controlled, and the air conditioning equipment 20 is provided to adjust them. Adjusting the temperature inside the entire factory would result in high air conditioning costs, so it is desirable to air condition only the plant cultivation environment.

In the air conditioning equipment 20 of the plant cultivation device 1 shown in Figure 2, the air conditioning duct 21 extends from a blower (not shown) and is arranged to extend along the LED board 12 of the lighting equipment 10. The air conditioning duct 21 is arranged below the LED board 12 and does not directly block the light emitted from the LED light source 13.

As shown in Figures 3 and 4, the air conditioning duct 21 is installed to cover the lower and side portions of the LED board 12 with gaps, which serve as air passages 22. The air outlet 23 is located on the reflective surface 15 side of the canopy 14 and is configured to blow air sent from the blower toward the reflective surface 15. The blown air is agitated when it hits the reflective surface 15 of the canopy 14, as indicated by the dashed arrow D in Figures 3 and 4, and moves to the plant growing space below.

If the air outlet 23 is formed below the air conditioning duct 21, the cold air may directly hit the growing plants. If the cold air is directed at the same leaf surface or stem for a long period of time, the low discharge temperature may damage the area directly hit by the cold air. Furthermore, for plants that have grown tall enough to be harvested, the distance between adjacent plants is small. Therefore, if the cold air is discharged directly toward the plants, turbulence will occur near the plants, resulting in areas that are not hit by the cold air. As a result, temperature unevenness may occur, potentially resulting in inconsistent plant growth. Therefore, it is not desirable to provide an air outlet below the air conditioning duct 21 and direct the cold air directly toward the plants.
In the air conditioning device 20 of this embodiment, the air outlets are not directly directed at the plants, preventing the cool air from directly hitting the plants. Furthermore, the air blown out from the air outlets 23 hits the reflective surface 15, is agitated, and moves to the plant growth space below, preventing turbulence near the plants. Furthermore, the air in the plant growth space can escape through the gap 34a between the cultivation tank 30 and the side wall 34. This allows the air to be distributed evenly, preventing temperature variations.

Furthermore, the air passing through the air conditioning duct 21 passes around the LED board 12, and can therefore also be used to cool the LED board 12. In other words, by placing the LED board 12 inside the air conditioning duct 21, the cooling effect on the LED board 12 is enhanced, which has the effect of extending the lifespan of the LED light source 13 and the LED board 12.
This air conditioning device 20 can also be applied as is to the plant cultivation devices 1A and 1B shown in FIGS.

In addition, as a measure to mitigate uneven illuminance, a highly reflective material may be attached to the outer surface of the air conditioning duct 21. By attaching a highly reflective material to the surface of the air conditioning duct 21, the light reflection efficiency can be increased in combination with the light reflection from the surface of the cultivation panel 32.

Note that while the light emitted from the LED light source 13 becomes parallel rays in the cross section of the lighting device 10 in the width direction (Y direction), the light emitted from the LED light source 13 becomes scattered light in the longitudinal direction (X direction) of the lighting device 10. Therefore, when the light reflected by the top surface reaches the surface of the planar cultivation panel 32, all light except for that absorbed by the plants is diffused from the surface of the cultivation panel 32. As a result, the reflected light is somewhat uniform within the plant cultivation space surrounded by the reflective surface 15 of the shade 14, the side wall 34, and the cultivation panel 32, which reduces uneven illuminance that occurs in areas shaded by the air conditioning duct 21.

The plant cultivation device 1, which is an embodiment of the present invention, has been described above using the figures. However, the above embodiment is merely an example to facilitate understanding of the present invention and does not limit the present invention. For example, the plant cultivation device 1 has been described as an apparatus that irradiates light onto plants grown hydroponically, but the plant cultivation device 1 may also be used for plants grown in soil on the ground.

1, 1A, 1B, 101a, 101b Plant cultivation device
10, 10A Lighting equipment 11, 11A, 11B Lighting unit 12, 12B LED board 13, 13A, 113a, 113b LED light source 13a, 13Aa LED light source in the first row 13b, 13Ab LED light source in the second row 13Ac LED light source 14 in the third row Shade 15 Reflective surface 15a, 15Aa First region 15b, 15Ab Second region 15Ac Third region 16 Axis 20 Air conditioner 21 Air conditioning duct (casing)
22 Air passage 23 Outlet 30, 130 Cultivation tank 31 Hydroponic nutrient solution 32 Cultivation panel 33, 133a, 133b Plant 34 Side wall 34a Gap 36 Support member C Center lines R1, R2, R3, Ra, Rb Irradiation angle

Claims (8)

A plant cultivation device equipped with lighting equipment,
The lighting device includes:
An LED light source;
an LED substrate on which the LED light source is mounted;
a cover that covers the LED light source and the LED substrate,
the shade has a curved reflective surface that includes a quadratic curve having a focus at the position of the LED light source in a vertical cross section passing through the LED light source,
The LED light source is arranged with its irradiation direction directed toward the reflecting surface of the shade , and the plant being cultivated is irradiated with parallel light reflected by the reflecting surface . The LED substrate is formed in an elongated shape,
The LED light sources are arranged in a line along the LED substrate,
The plant cultivation device according to claim 1 , wherein the shade extends along a direction in which the plurality of LED light sources are arranged. The plurality of LED light sources are arranged in two rows on the LED substrate,
The reflecting surface of the shade has a first region and a second region, and the first region and the second region are arranged at positions that are line-symmetrical with respect to a center line of the reflecting surface,
3. The plant cultivation device according to claim 2, wherein the plurality of LED light sources arranged in a first row are arranged so that their irradiation direction faces the first area, and the plurality of LED light sources arranged in a second row are arranged so that their irradiation direction faces the second area. the plurality of LED light sources are arranged in a row on the LED substrate;
The plant cultivation device according to claim 2, wherein the LED substrate is disposed so that the irradiation direction of the LED light source is inclined at a predetermined angle from the vertical direction in the longitudinal cross section. A plant cultivation device equipped with lighting equipment,
The lighting device includes:
An LED light source;
an LED substrate on which the LED light source is mounted;
a cover that covers the LED light source and the LED substrate,
the shade has a curved reflective surface that includes a quadratic curve having a focus at the position of the LED light source in a vertical cross section passing through the LED light source,
The LED light source is arranged such that the illumination direction is directed toward the reflective surface of the shade ,
The LED substrate is formed in an elongated shape,
The LED light sources are arranged in a line along the LED substrate,
The plurality of LED light sources are arranged in three rows on the LED substrate,
the reflecting surface of the shade has a first region, a second region, and a third region, the first region and the second region are arranged at positions that are line-symmetrical with respect to a center line of the reflecting surface, and the third region is located between the first region and the second region,
The plant cultivation device is characterized in that the plurality of LED light sources arranged in a first row are arranged so that their irradiation direction is toward the first area, the plurality of LED light sources arranged in a second row are arranged so that their irradiation direction is toward the second area, and the plurality of LED light sources arranged in a third row are arranged so that their irradiation direction is toward the third area . A plant cultivation device according to any one of claims 1 to 5, characterized in that the LED substrate on which the LED light source is mounted is mounted rotatably about an axis that is perpendicular to the longitudinal section and passes through the LED substrate. The plant cultivation device described in claim 6, characterized in that it includes a housing that surrounds the LED board and rotates together with the LED board around the axis. Equipped with air conditioning equipment,
the air conditioning device has an air conditioning duct arranged below the LED board,
The plant cultivation device according to any one of claims 1 to 7, characterized in that in the air conditioning duct, an air outlet through which air is blown out toward the reflective surface is formed on the reflective surface side of the shade.